Signature Chain is a public-beta prototype for preparing and testing structured agreements with constrained AI and wallet-based signatures. Users describe a bilateral USDC agreement, review a readable proposal, and decide whether to apply its fields to a fixed template. The assistant can suggest only an agreement title, amount, and deadline; it does not write contract code, sign, or initiate transactions. In the active test flow, two distinct wallets on Base Sepolia sign the same locked revision using EIP-712. The prototype verifies those acceptances but does not deploy contracts, request token approvals, move funds, or execute agreements.

The service emphasizes user control, visible terms, and separation between proposal, review, signing, and any future execution. Its agreement preview includes items such as release rules, deadlines, fees, cancellation, and refund conditions. Signature Chain also outlines potential future templates for escrow, milestone payments, inheritance, token exchange, and real-estate coordination, while noting that these require reviewed code and, where appropriate, qualified partners.